Sign a File to Create a .p7m File

Delphi example to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

Download Chilkat Crypt ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATCRYPT2Lib_TLB,
    CHILKATCERTIFICATELib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
success: Integer;
ccs: TChilkatCreateCS;
certStore: CHILKATCERTIFICATELib_TLB.IChilkatCertStore;
cert: CHILKATCRYPT2Lib_TLB.IChilkatCert;

begin
crypt := TChilkatCrypt2.Create(Self);

//  Any string argument automatically begins the 30-day trial.
success := crypt.UnlockComponent('30-day trial');
if (success <> 1) then
  begin
    ShowMessage('Crypt component unlock failed');
    Exit;
  end;

//  Find our digital certificate from the Current User certificate store.
ccs := TChilkatCreateCS.Create(Self);

certStore := ccs.OpenCurrentUserStore();

cert := certStore.FindCertBySubjectCN('Chilkat Software, Inc.') As CHILKATCRYPT2Lib_TLB.IChilkatCert;
if (cert = nil ) then
  begin
    ShowMessage(cert.LastErrorText);

    Exit;
  end;

//  Tell the crypt component to use this cert.
crypt.SetSigningCert(cert As CHILKATCRYPT2Lib_TLB.IChilkatCert);

//  We can sign any type of file, creating a .p7s as output:
success := crypt.CreateP7M('test.xml','test.p7m');
if (success = 0) then
  begin
    ShowMessage(crypt.LastErrorText);

    Exit;
  end;

//  Verify and restore the original file:
crypt.SetVerifyCert(cert As CHILKATCRYPT2Lib_TLB.IChilkatCert);

success := crypt.VerifyP7M('test.p7m','testRestored.xml');
if (success = 0) then
  begin
    ShowMessage(crypt.LastErrorText);

    Exit;
  end;

ShowMessage('Success!');
end;